The invention refers to a round baler having a bale chamber covered at least substantially by side walls and flexible bale forming means.
U.S. Pat. No. 5,931,089 discloses a round baler having multiple rollers rotatably journalled in a chassis to carry a set of belts. An inlet to a bale chamber is provided downstream of a pick-up between two fixed rollers. A span of belts bridging this inlet is engaged by incoming crop and deflects towards the bale chamber to create a loop. The incoming crop increases the bale in said loop until it reaches a maximum diameter. As soon as the maximum diameter is reached, a gate carrying one of the rollers limiting the inlet is raised and the loop opens to the ground to dump the bale.
In xe2x80x9cFMO 141 B D-00, Hay and Forage Harvestingxe2x80x9d of Deere and Company pages 153 and 154 is disclosed a type of round baler which had been common in the 1970""s. This type had two spaced side walls each of one piece and a pair of arms to which is attached a frame carrying three rollers over which belts are trained. In the bottom area a bottom conveyor of a wide belt is provided, on which the bale is supported during formation. When the round baler is empty, a lower front roller assumes a position immediately above said bottom conveyor and close to an inlet of the bale forming chamber. The more the bale approaches its maximum diameter, the bigger will be a part of the bale, that extends over the rear edges of side walls.
The problem to be solved with respect to these prior art balers is either the weight of the gate which has to be handled in order to get the bale out of the bale chamber or the costs of a bottom conveyor.
According to the present invention, there is provided a large round baler having an improved bale forming arrangement for overcoming the aforementioned problems associated with prior art balers.
The objectives of the present invention are accomplished by a structure including a roller located outside the bale chamber to train the bale forming means and to carry the bale, and for allowing just this roller to move in order to open the bale chamber at the rear of the baler to dump the bale onto the ground. Moving just one roller results in much less weight being moved than when moving a complete gate with several rollers and stiff side walls, as is the case with the prior art balers. Furthermore, a single roller may be moved on a quite complex track as opposed to a part of a circle as given by the movement of the gate. The arm supporting the single roller may be pivoted about a single axis or moved a long a path either defined by a guide or achieved by a multi-sectional arm having controls between the sections for varying their relative positions. A bottom conveyor is omitted, since the arms with the roller may be positioned under the bale and since the arm can slip under the side walls to the front and close to the center of gravity of the bale, the arms may carry the weight without being exposed to extreme bending forces.
Two rollers on the pair of arms permit a better routing of the bale forming means and to keep sections of the belts away from other moving parts. The distance between the rollers may be fixed or variable, whereas a variation of the distance may be achieved by power actuators like hydraulic motors or the like.
While in principle it would be possible to control the position of the arm manually by means of a link or the like, it is more convenient, more powerful, more flexible, and less dangerous to do it via a power actuator like a hydraulic motor or an electric motor and preferably either remote controlled or controlled by means of sensors, etc.
The routing of the bale forming means, the tension in them, and the location of the loop delimiting the bale chamber can be adjusted, modified, and controlled, if a second arm with one or more rollers is provided to train the flexible bale forming means.
While in general it would be possible to have an individual pivot axis for each pair of arms, both pairs of arms could be moved without limits and conflicts, if they are rotated or pivoted about the same axis, with different arm lengths preferably.
An overload as well as a high tension in the flexible bale forming means is achieved by a roller applied by an actuator, like a spring or any other tension means. Such an actuator or power actuator can be a gas spring, a mechanical coil or leaf spring or a hydraulic piston moved against a preferably variable pressure. Preferably this roller is kept in a guide to guarantee a roller movement and thus a tensioning or loosening of the bale forming means without canting or twisting.
A carrier on the moveable arms with one or more rollers on it permits to bring the rollers in the right position and to route the bale forming means as needed. While the position of the carrier is fixed as opposed to moveable, it could be attached in different positions depending on the configuration of the baler or the like.
Fastening the carrier and the rollers with it moveably with respect to the arms allows the rollers to be brought into an optimum position during the movement of the arm about its pivoting axis. This could be helpful to change the tension in the bale forming means, to route the bale forming means through tights areas, etc.
In order to have an inlet of fixed width which corresponds to the infeed geometry of an upstream pick-up, two rollers of a fixed distance may be used, which rollers may be a support roller in the bottom and a stripper roller on the top. One of these rollers could be located on the arm and swing away, when the bale chamber is opened.
If the bale forming means are trained over the stationary roller kept rotatably by the chassis and delimiting the inlet on the side remote from the bale chamber, no starter roller is required and thus there is no risk of wrapping in that area. Furthermore the crop gets in immediate contact with the bale forming means and can start rolling.
In an embodiment, in which the flexible bale forming means are trained over the stationary roller(s) on the side facing the bale chamber, a small chamber is provided, which has a driven starter roller at one side, which assists in holding the crop and starting the bale core.
The path of the roller or the rollers on the arm(s) is predetermined and easy to achieve, if it follows the contour of the side walls, which may be formed such, that a certain routing of, and tension in, the bale forming means is achieved.
The possibility to change the distance between the side walls allows to produce bales of different size and volume and thus to accommodate to the dimension of a truck or the like. The distance can be varied if the side walls are moved on or with the shafts on which the arms are journalled.
Stops at the arms, roller or carrier fixed on the arms, are useful to act against the bending forces applied to the side walls by the crop. Thus the bale chamber retains a constant width even if it is filled completely. Such stops could contain rollers, gliders or the like.
Belts and chains with slats thereon are excellent bale forming means, since they can be trained in a very flexible way over rollers in different and even changing positions.
If the peripheral edges of the side walls are distant in the plane of their substantial extension from any adjacent or close component, like a frame, pick-up, etc., the rollers on the arms can be moved in a circular path around the side walls to perform an endless cycle.